,,,, ,,,,,,,,,,,, >> schieffer: today on "face the nation," america on edge as the u.s. government issues a worldwide terror alert. 22 u.s. embassies are closed because officials say they've uncovered a possible terror threat from al qaeda. we'll have reports on that and get the latest from the chairman of the house homeland security committee, michael mccaul. then we'll turn to the week's other big story-- the fallout from russia granting asylum to n.s.a. leaker edward snowden. >> russia has stabbed us in the back and each day that snowden is allowed to roam free is another twist of the knife. >> schieffer: we'll hear from new york democrat chuck schumer and we'll talk with house budget committee chairman paul ryan. plus analysis from the "washington post's" dan